Prior methods for obtaining directional range information include laser range sensors, cameras, ultrasound, optical proximity sensors, and multiple independent capacitance proximity sensors. Laser sensors require complicated, expensive, and often large scanning mechanisms to steer the laser beam, and their performance can be adversely affected by object surface characteristics. Cameras also tend to be comparatively large, complicated, and expensive, and the task of processing the image is computationally intensive, even when dedicated targets are placed on the objects in the image. Ultrasound sensors are less precise and less physically distributed than capacitance proximity sensors, and either multiple sensors or some form of steering mechanism must be used. Ultrasound does not work in outer space. Optical proximity sensors are also less physically distributed necessitating many independent sensors or a complicated steering mechanism to be used. Sensing range is generally significantly less than capacitance proximity sensors, and ambient lighting conditions can interfere with their operation.
Multiple independent capacitance proximity sensors require more support electronics and hardware, they require more space, they may operationally interfere with each other, and they do not have the capability to change the amount that each sensing field overlaps with the others.
The present invention provides a means of obtaining directional proximity sensing while maintaining the inherent attributes of the basic Driven Shielding Capacitive Proximity Sensor. The present invention sensor is light weight, robust, simple, and inexpensive, and a minimum amount of electronics is needed to steer the sensing field. In addition, unlike video image processing, interpretation of the sensor output is extremely simple.